Dunnage bags are commonly used in the transportation industry to insure that large articles packed within a vehicle, such as a railroad car or a truck, are not damaged during shipment as a result of a mechanical shock. For example, when large articles are packed within a crate and such crates are placed within a railroad car, the articles contained within the crates might be damaged when the railroad car was coupled to a train. To minimize the possibility of articles being damaged in this manner, a small space may be left between each crate. In each of these spaces, an inflatable bag may be disposed and inflated so as to provide, in effect, a pneumatic cushion between each of the crates and between the crates and the walls of the freight car.
Initially, dunnage bags were constructed of heavy guage, rubberized material, so as to withstand the mechanical stresses to which they were subjected. However, the cost of such dunnage bags was sufficiently high as to require their re-use. Since the re-use of a dunnage bag often required the reshipping thereof to a point of origin or the storage of such bags for future use, it was conceived that a need existed for disposable dunnage bags. As a result, dunnage bags were developed which employed relatively light weight, thermoplastic bladders encased within a number of plies of paper. In such a construction, the light weight, thermoplastic bladder retained the air used for inflation and the plurality of papers plies supplied the required strength.